Getting yelped

Our little shop took years to build, and yet at the same time we still aren’t done trying to build it. Operated by my wife Beth at the front desk and myself as the only technician we have taken the path less traveled when it comes to operating an automotive repair shop. Today people from all over the county and even other shops rely on us to solve the toughest problems that can occur on some of these cars. To be that shop, that tech, I have had to work harder than everyone else that I have ever been around both on the job and at home studying when I should have been off the job. That’s an extension of a habit that started in the late 70’s when I was a young technician and was struggling to learn how to be a good mechanic. When someone would say something like “You’ll never be any good” I took the anger and hurt that I felt and used it to push myself to study so that I would be the best technician that I could be and hopefully someday show them that they were wrong. I must say there have been many times that I wish that I would have simply walked from this career away instead of constantly striving to improve myself and my capabilities. Early in the eighties I started studying electronics because of how poor the wages and working conditions were and the plan then was that I was going to quit fixing cars and go make a living working on computers. Little did I know how that education would make me better at dealing with the computerized cars way back then as well as today and that is part of what makes our little shop different.

Have you ever taken your car into a shop for one thing and come out with a list of recommendations that cost hundreds if not a thousand or more dollars?

We don’t up sell maintenance services to try and generate easy dollars like so many places do, I’ve never believed in that approach. Back when that first started the business guru’s were running around telling shop owners “You can’t make money fixing cars, sell services”. They would point out that it took a much more experienced technician (who of course cost more to employ) to fix cars while there were fewer things to go wrong and greater profits if the shop simply concentrated on just doing the easiest work. I had been a technician for about ten years when this was all going down and had been gaining some recognition for my efforts and here were “experts” telling shop owners they shouldn’t be employing guys like me who could take on anything, they only needed entry level people to install tires, batteries, brakes, and to flush fluids.   

It was strange how it turned from I could never be good enough as a mechanic to being too good to allow a shop to be profitable in such a short time but that’s a mechanics life in a nutshell. It seems no matter where a tech is in his/her career there is always someone going out of their way to cut them down, and now I find this little gem of a review in Yelp. “One of the worst experiences I have ever had, the man is very confrontational and insulting. His character and workmanship is very very poor.” Adam W.

Well Adam I’d like to address this with you, but I can’t because there is no Adam W in our customer list. At the same time I’m afraid that I might live up to being confrontational at this point because working  90-100 weeks for the last thirty eight years has me pretty worn out and there just isn’t enough left in the tank to try and stand back up again when someone is trying to knock me down.  The facts are, our regular customer’s opinions of us and our shop don’t match yours. Plus the fact that we are the hero’s to thousands of people who were sent by their regular shop for us to solve a nightmare issue who routinely re-recommend us when someone else is dealing with a tough diagnostic problem.

The interesting part is we don’t actually make a good living dealing with these kinds of problems. The cost of the O.E. scan tools that we have been buying for the last fourteen years, while our competition hasn’t been making a similar investment has been crippling for us. The continued training expense reached a point that it turned into a way to supplement the shops tooling expenses when I started working a second career as a continuing educational instructor.  (That’s how I’ve been hitting the 100/hr weeks of late) Many of the problems that we solve on these nightmare cars take significantly more time to figure out and repair then we can bill for and keep the customers immediate interests in mind. In a lot of ways we prove that the guru’s were right, you can’t make money fixing these cars but that is what our shop is all about and since our customers need us we push onwards, in spite of our own personal challenges.

During the last eight years Beth’s epilepsy got so bad that surgery became the only chance for her to get any relief. Last year they took out the entire right temporal lobe of her brain to try and stop the clusters of seizures that she was experiencing.  Thank-fully that has stopped the periods where she could take twenty to thirty seizures in a cluster every three weeks, but didn’t completely eliminate them. The doctors are now starting to evaluate and try to decide just what to do next. For the moment they are working with the medications and we know not to expect a perfect result but any brief period that see’s her free from events is a blessing.

Three weeks before her surgery we took the only one week vacation we ever had since we got married thirty four years ago, previously we had only one four day vacation back in ’95. We don’t live beyond our means and that’s all we have ever gotten to have. We only took that one before her surgery because we didn’t know what we were going to have after it.

So now you all know a little more about us, and if you want a shop that takes pride at going straight in at a vehicle problem, solves it, and gets straight back out without trying to sell you everything under the sun, then we are who you are looking for. As a three time NAPA ASE tech of the year, an ASE Certified Master Technician since 1982, two time GM Master Technician, a member of the GM Master technician Advisory Council, a technical writer and Instructor, and I even host my own live call in radio show and a RepairPal Certified shop we are doing everything we can possibly do to be ready when you need us. We are far from perfect and sill not afraid to work harder than the guy down the street all while walking  the road less traveled.

Fuse 41 Ford Ranger

A 2001 Ford Ranger was blowing fuse 41 if the vehicle moved at all. A local transmission shop had the truck because when the fuse blew it caused a loss of power to the transmission solenoid pack. When they didn’t find the problem they sent it onto us for diagnostics. When a fuse blows as soon as you plug a new one in, the routine a technician should use is to substitute a load in its place in order to power up the circuit. A headlight works very well for this.  By connecting the headlight in place of the fuse “the short” simply completes the ground circuit that is created and the headlight lights up. Then to do the diagnostics all the tech has to do is follow the current flowing in the circuit to the problem by measuring the current that is flowing and then follow the wiring harness using a low amps current probe. That’s a high tech way to make easy work of what used to be a difficult problem.

With this Ranger the fuse didn’t blow immediately most of the time, but it could blow so quickly sometimes that the truck didn’t even pull out from starting it up. That meant a different approach needed to be taken for this problem. By installing a circuit breaker via a jumper harness the current probe could be connected to the jumper harness and the current that was flowing in the circuit could be monitored. This first capture was the current that was flowing in the circuit when the connections were made and the spike occurred as the technician was getting into the truck to try and take it for a road test.

 

Here is a low amps probe connected to the circuit with jumper wires and a circuit breaker in place of the fuse.

 

 

 

 

 

For a diagnostic tech, that’s a great result for the first test. Just disturbing the body of the vehicle generated a current spike, that’s a classic example of an abraded wiring harness that is grounding somewhere. Now it’s just a matter of finding the location of the harness failure.

 

 

 

Fuse 41 feeds the transmission solenoids as mentioned previously, it also feeds all of the O2 sensor heater circuits and the canister vent solenoid. Most of the circuit is visible without too much effort, the only part that isn’t easy to see is the part of the harness that is inside the transmission. The goal now would be to prove if the problem is inside or outside of transmission portion of harness if possible. If a visual inspection of the harness doesn’t reveal the cause of the problem, then if necessary the plan will be to use a second current probe on just the transmission harness.  That way the next time a current spike occurs, if both current probes show the spike then the problem would be confirmed to be inside the transmission.

Inspecting the harness and the O2 sensor connections didn’t reveal any problems, but when the vent solenoid portion of the harness was checked the harness was clearly abraded and intermittently contacting the bed of the truck.  The repair required the replacement of the pig tail connector for the vent solenoid and by creating some relief for the assembly the wire could be assured to not abrade again in the future.  While this event was very easy and straight forward, by taking a disciplined approach it wouldn’t have mattered if this would have been a more complicated problem. The solution would have been achieved in an efficient manor and that’s the key when it comes to doing diagnostics. A solid diagnostic routine is one that is repeatable and doesn’t fall for the inherent traps that are based on relying on silver bullets. Fuse 41 has been known to fail because of a bad heater circuit inside of any one of the O2 sensors. It’s been known to fail because of problems with the solenoid pack or its harness inside the transmission. There can also be main harness issues as well as the problem this time of the vent solenoid portion of the circuit like this truck, but none of that matters if a tech can come up with his/her own game plan and again be able to take a disciplined approach, he/she will go straight at the problem and that's exactly what the customer needs them to be able to do.

The Colorado Final, and a Shout to Jim Garrido for the strategy that was used to diagnose it.

The owner took a nice ride up to Erie Pa and did some shopping at the wineries for the holidays. That gave him the trip that he needed to run the fuel out of the truck, and have some real time for the cleaner to do its job. Over the weekend he had a couple more shorter trips and by Monday when he stopped by the shop the smile on his face was promising. He reported that he could clearly feel a difference in the truck, he was certain that its performance was notably improved.  

The thing to do now was to collect some data with the very same checks that were done initially. What was found was at idle the long term trim was 24% and the short term was 19 for a total of 43%. That’s better but only marginally. At 2500rpm no load it was 19% long term and 12% short term. That was clearly better at 31% total trim but still not in control. At 1500rpm in gear against the brakes it was also much improved and in the total range of 30%. Its important to note that the same two monitors were still not complete, the evaporative and the catalyst. With our sudden cold snap, the evaporative monitor not completing was no surprise since a number of the code enable criteria have minimum ambient temperature requirements in the 40f range. The catalyst monitor didn’t run because the fuel trims were still too lean to allow that to take place at idle.  While the fact that the fresh fuel and the cleaner made a difference was promising, there was still a pretty good chance that the truck might need new injectors. The owner planned to return in two days so we could check one last time.

On Wednesday afternoon he returned only this time he reported that the light was back on. However it was running even better than it was on Monday. So what do you do with the light being back on? The right thing to do is approach it exactly as any other repair visit, and that means forget everything you already know while you are doing the diagnostics. With that plan in mind here is what was found with the truck.

The code was a P0171 again, lean air/fuel ratio. The freeze frame showed that it had set at idle. Starting the truck up the total fuel trims were 40%, with the long term being 25% of that. Speeding the engine up to 2500rpm the total fuel trim dropped to 20%, with the long term at 19% and the short term at 1%, that’s a big difference from the previous data! Loading it up against the brakes at 1500 rpm the total trim was below 10% with the long term at 7% and the short term varying around 2%. That’s good enough, not perfect, but good enough. So why was it so lean at idle still, and what would you do at this point?

False air, or a vacuum leak are quite probable now because they will have a big impact with low engine speed and low cylinder charge demand. Under faster engine speeds there isn’t as much time to impact the air fuel ratio, under load against the brakes there is little to no manifold vacuum so a vacuum leak can’t impact the air fuel ratio much at all. That means its time to get the smoke machine out and check for a leak. With the mass airflow sensor at the air cleaner, wrapping the air filter with plastic wrap will allow all of the intake system to be checked. A few moments later smoke was seen pouring out from under the resonance chamber that is in-between the MAF and the throttle body. Pulling it off the breather hose wasn’t connected to the valve cover, and the oil staining in the area suggested that it had been off of there for some time.

Once it was secured back in place, the plastic wrap removed from the air filter and re-installed,  the fuel trims were reset with the scan tool and it was time to re-evaluate the fuel trims. By resetting the fuel trim, the short term trim alone had to make all of the correction, at idle that was now 8%, 2500 rpm no load 5% and against the brakes 5%. The truck was fixed but we weren’t quite done yet, he still needed his emissions test.  In Pa he passes with one monitor incomplete, and in this case that was going to be the evaporative monitor because of the ambient temperature as well as needing to have a cold soak where the coolant and intake air temperatures had to drop within the code enable criteria range.

The customer was provided specific instructions for how to drive a cycle and about twenty minutes later he returned with enough monitors completed to allow the emissions test to run and his sticker finally issued.

This truck and how it was diagnosed and repaired is based on training case studies written into CTI classes by Jim Garrido.  The best way to thank him for sharing this kind of information is to attend some of his classes ASAP.

2005 Colorado Too Lean, continued

At this point the truck is confirmed to be running too lean, but why is it too lean? This could be a fuel quality issue, fuel pressure problem, injector problem or it could be a base calculation error. The more that can be ruled out with scan data, the less physical testing that needs to be done to prove what is wrong.  Some of the things to think about are what information the PCM uses to make its base fuel calculation. GM uses a mass airflow sensor (MAF), and the software takes that MAF value and calculates the engine load and from there what the injector pulse width should be under those conditions to provide the engine with the right amount of fuel.  While on a road test the accuracy of the MAF can be checked by watching that engine load calculation in scan data. During a wide open throttle acceleration a snapshot of the engine data can be captured and then later played back so that the engine load pid can be examined to see if the MAF sensor reported.

During the road test it was easy to get the MAF to report 100% engine load.  So the PCM should have been calculating the correct base pulse width and turning the injectors on long enough for the engine to get the right amount of fuel. However it was still very lean under all phases of operation and the fuel trims were adding 40-45% to the injector pulse width. One note-able observation was that during a hard acceleration where the PCM commands an open loop enrichment to provide full power, all four O2 sensors reported over .88 volts, and then on a closed throttle deceleration they all fell to 0volts showing good amplitude and reaction. At this point it’s back to the shop for the last phase of testing.

Once back in the shop the fuel pressure was confirmed to be at 63 psi, with enough fuel pressure and fuel volume that mean the only two things left that could be causing the problem were fuel composition/quality or restricted injectors. With the vehicle otherwise operating reasonably well there was an option on how to proceed and its one that the customer chose to try. Instead of doing specific fuel quality testing and manually cleaning the injectors, he was to go fill up at a Top Tier fuel station, and add a very specific fuel injector cleaner, Chevron Techron to the tank.  His travel plans included one immediate trip of about 250 miles to start the injector cleaning process and run all of the old fuel out of the tank. Then we would check the fuel trims and see if anything changed after he refilled the tank.

To be continued…

Fuel trim Issue 2005 Chevrolet Colorado

A few years ago a fellow showed up with a 2005 Chevrolet Colorado with a 4.2l 6cyl. It had a misfire at idle that was proven to be valve seat failure which was common for those engines. We didn’t get to do the repair because of a special policy set up by the manufacturer.

Just this past week the customer came back to us after numerous attempts at other shops to have a check engine light issue repaired. The vehicle couldn’t even have its emissions test run because of two incomplete monitors, the catalyst and the evaporative emissions systems.

When dealing with one of these the first step is to retrieve and write down any codes, check and capture freeze frame and failure record data and then get a good road test in so that you have a good baseline on how the emissions system on the car is functioning.

There was a P0171 set in the computer’s memory, that’s a lean air/fuel ratio code. Checking the freeze frame the code set at 25% engine load and 33 mph, that’s a light throttle condition. Now the question that has to be asked yet is whether this is the only time that the engine is too lean or not. The answer to that is easy, start the engine and get the truck into closed loop. Check the fuel trims at idle, no load and what I saw was the long term trim at +25%, and the short term trim +20%, that’s a total correction of 45% which is a very lean condition. The next step is to try and determine if this is a vacuum leak or some other fuel issue. To do that the engine speed is increased to 2500 rpm while again monitoring the fuel trims. They were still +25% long term and +20% short term just like the no load idle. Generally if the problem is a vacuum leak there will be a smaller correction at the higher speed because there is less time for the leak to impact the air/fuel ratio. The next step is to put the car into gear against the brakes and speed the engine up to around 1500rpm. Now there is almost no manifold vacuum, and a vacuum leak would be nullified if that was the cause of the problem.  The trims were still a total correction in the 40% range.

This is information that is gathered before the car ever moved from the spot the customer parked it at. Think about what the next step should be, and what the possible causes are. I’ll post the next part of this vehicle in a few days.

Just good people who do a difficult job

A couple years ago NBC news, Jeff Rossen, did a "sting" on auto repair shops using a defective AC relay. Like most of those attempts they found some things that really are bad about the repair trade. The caught some dishonest people and most techs want nothing more than to have people like that out of our trade. At the same time they also found things that are actually bad that they praised!. In the end they really only succeeded in exposing some people who were giving all shops and techs a bad name, but did nothing about the underlying causes for the behavior.

I've made it a point to be a thorn in the side of one of the groups that participated in that sting. They are portrayed as experts and sat in judgment of shops and techs and routinely were giving advice to consumers that was flat out wrong. I always made it clear why I was there, but the individuals who were involved in the sting refused to subject themselves directly to my scrutiny. That was a wise move on their part, they really didn't have anything to gain,  and besides they didn't have the expertise at auto repair that they claimed and I would have made that very evident.

Well this week Jeff Rossen came out with this "sting". It speaks for itself and while not perfect its good enough and for my part I'll steal a line from Harry Potter. Mischief Managed. Maybe the pressure that I brought had something to do with this, maybe it didn't. But it's about time the public gets to see real techs doing what they do everyday, and that's their best to try and take care of their customers.

http://www.today.com/news/could-little-dashboard-light-cost-you-big-bucks-2D11603387

I could ony advise the techs to find new jobs as fast as they could.

Another technician wrote a post about a dealership who has restructured their service department so that they have some techs who only do diagnostics, and then they pass the cars onto other techs to do the actual repair. The real kicker is that they take two productive hours off of the regular techs each day to make a pool from which to pay the diagnostic techs. I can only wonder how people who know so little about being a technician get into a management position over them where they get to make these kinds of decisions.

 

I could see myself as potentially one of the diagnostic guys. What I can't see is handing the work off to someone else once the diagnostics are completed. Fixing the car means also doing the actual repair  because that serves to reinforce the intuitive side of a technicians knowledge and experience. As one of the other posters noted anytime the process doesn't work and a car isn't repaired, who do you point the finger at? IMO, the moment you have to start pointing fingers you have all the proof that you needed to prove that this wasn't a good idea to start with.

 

Getting good at diagnostics requires just plain getting good at fixing cars, plus a whole lot of hard work on top of that studying and developing as Jim Garrido says a good game plan. I think most of the top techs will agree with me that there were a lot of mistakes on the way to figuring out their game plans, and most of the lessons taught by those mistakes were (and occasionally still are) learned the hard way. One of the toughest hurdles was to learn to take a patient disciplined approach, especially when the store only wants to pay pennies no matter how much time needed to be spent doing diagnostics. I have 1999 Jaguar XK8 in the shop right now that makes for a good analog.

 

A week ago a shop sent it to me for a P1646 which his information showed to be fuel pump #2 relay control circuit issue. Except that the #2 pump is only used on the super charged cars, so right away he had no idea what was going on with this car. It took some researching and it turned out that P1646 is for the heater circuit upstream sensor bank A. But instead of having me go through the steps to prove what the failure was and complete the repair the shop stopped the diagnostics and took it back to their place to just throw a sensor in it. In the process of doing that they bought a "very inexpensive one" compared to the O.E. that I would have recommended and to install it they had to splice the connector from the original sensor. Two key starts later, the light was back on and the code had reset, so now they wanted it tested completely.

 

If you are able to look at that paragraph and see quite a few miss-steps, from not fully diagnosing the problem at any time, to them having inadequate service information, and then using questionable parts and repair habits you see how a lot of shops run. By the numbers, however 95% of the time they were going to get the final outcome correct by just slamming that sensor if they had only used a quality part so one can argue there is a potential reward for that approach. However instead of fixing the car, they added yet another variable to the problem and that has both of us further away from fixing the car than they were a week ago. At least they broke tradition at this point and are going to let me prove what is going on before they just slam another O2 sensor even if it is the correct part this time.

 

The real problem isn't whether what that dealer is trying to do is legal or not, it's how many things will go wrong with it because management hasn't thought it out completely.

The above scenario where some techs are doing the diagnostics and while others are replacing the parts are going to create a lot of Jaguars, and when they slam the parts and get it right they will turn around and feel that the lower level tech was all they needed. While if they still rush it at all they will defeat the whole idea of having the diagnostic techs in the first place and that's when the finger pointing will start. One of the worst parts of this is they have just added a glass ceiling to the career path for the next generation of techs who should be learning to be their diagnostic techs of the future, and they are taking two hours off of them each day  to pay for all of this. To me that shows that they don't care about technician retention nor does the management understand the long term technician career path.